The MGN61844 is a Schneider Electric Multi9 C60H-DC miniature circuit breaker — a 2-pole, 4 A thermal-magnetic unit built for DC distribution circuits. The C-curve trips at 8.5 x In (34 A magnetic), which suits cable protection and moderate inrush loads like DC contactor coils.
The breaking capacity drops as voltage climbs: 20 kA at 220 V DC, 20 kA at 250 V DC, 10 kA at 440 V DC, and 6 kA at 500 V DC. That 6 kA at 500 V is the number to check if you're protecting a 500 V DC bus — it's lower than the headline 20 kA.
Panel integration
Clip-on DIN rail mount, 36 mm wide (4 x 9 mm pitches). Tunnel terminals accept up to 25 mm² rigid stranded or 16 mm² flexible; strip length 14 mm, torque to 2.5 N·m. IP20 finger-safe on the front, IP40 inside a modular enclosure. Padlockable toggle for lockout/tagout. The 73 mm depth leaves clearance behind a standard 80 mm deep enclosure.